On the use of manometry method for measurement of gas adsorption equilibria and characterization of clay texture with Derivative Isotherm Summation

Abstract

Gas adsorption is widely used for characterization of clays. Apart from “classical” experiment of nitrogen or other gases adsorption/desorption at cryogenic temperatures, allowing the determination of the specific surface area, partial mesopore and micropore volume and size distributions, gas adsorption can also be used for the characterization of clay surface texture (energetic heterogeneity) related to layered structure of clays. Derivative Isotherm Summation applied to high-resolution gas adsorption isotherms was shown to be a powerful tool to access energetic characteristics and ratio between basal and lateral faces of clay particles. To date, the method is not commonly employed for characterization of clays and other heterogeneous solids, probably due to specificity of high-resolution isotherms acquisition technique described in the original literature: quasi-equilibrium volumetry with gas injection by microleak. We illustrated in the present work a possibility to use widely available static manometric commercial gas adsorption analysers for this purpose.